Advanced Journal of Environmental Science and Technology ISSN: 2136-3468, Vol. 5 (4), pp. 245-246. May, 2018. © Advanced Scholars Journals

 Opinion Paper

Climate change and hypothalamic–pituitary–adrenal axis in livestock: what we know and what needs to be explored?

Angel P Sunny¹² M. Bagath¹ and V.Sejian^1,*

¹ICAR-National Institute of Animal Nutrition and Physiology, Adugodi, Hosur Road, Bangalore-560030

²Academy of Climate Change Education and Research, Kerala Agricultural University, Vellanikkara, Thrissur, Kerala

*Corresponding Author’s E-mail: [email protected] 

Accepted 1 May, 2018.

Background

Climate change causes unprecedented challenge to the entire development of livestock production system. Climate change will negatively impact the animal directly through elevated temperature and precipitation pattern variation and indirectly through the reduced quality and quantity of crop yield, water availability and increased disease outbreaks. Among the all climatic variables, heat stress is the most intriguing factor which affects livestock sector. Heat stress detrimentally affects the animal growth, production and reproduction, which culminates in severe economic loss to the livestock farmers. Among the various internal regulators, hypothalamic-pituitary-adrenal (HPA) axis play a primary role in streamlining the adaptive activities of heat stressed domestic livestock.Therefore, methodologies pertaining to measuring stress level are very crucial for studying animal adaptation and its associated mechanisms. The HPA axis activity is often measured by corticosteroid release as a means to evaluate stress and well-being in animals. Although, the sympatho adrenal medullary system also originates from HPA axis still its products epinephrine and nor-epinephrine are available only for a transient period of time. Therefore, stress levels are primarily measured by the changes associated with HPA axis and its end-prod­uct glucocorticoids, has traditionally been the primary means to make inferences about the stress response in animals. Hence, future research efforts are needed to study in depth the functionality associated with HPA axis at cellular and molecular level to establish the hidden intricacies of stress pathways. These efforts may yield suitable biological markers which may be useful in identifying livestock species with superior thermo-tolerance ability to heat stress. Hence, attempt has been made in this opinion paper to project to the readers the significance of HPA axis for having in-depth understanding of the stress pathways in livestock. These efforts are vital as the scientific community battles in its efforts to identify the most suitable breed specific for different agro-ecological zones.